JP2018066294A - engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine for a saddle riding type vehicle which heats a lubrication oil early and inhibits excessive temperature rise of the lubrication oil while inhibiting enlargement of the engine in a vertical direction.SOLUTION: An oil tank includes a first oil chamber and a second oil chamber. When a temperature of a lubrication oil supplied to a cylinder head is lower than a predetermined temperature, the lubrication oil in the first oil chamber is supplied to the cylinder head. When the temperature of the lubrication oil supplied to the cylinder head is higher than or equal to the predetermined temperature, at least the lubrication oil in the second oil chamber is supplied to the cylinder head. An outer surface of the first oil chamber and an outer surface of the second oil chamber are exposed to the outside of an engine. A sum of surfaces areas of an inner surface and the outer surface of the first oil chamber is smaller than a sum of surface areas of an inner surface and the outer surface of the second oil chamber.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an engine.

  When the temperature of the lubricating oil is low, such as when the engine is started, it is preferable to warm the lubricating oil early. Thereby, by reducing friction loss due to the lubricating oil at an early stage, it is possible to improve fuel efficiency or reduce exhaust gas.

  Therefore, in the field of automobiles, it has been proposed to use a two-layer oil pan. For example, in the engine of Patent Document 1, the oil pan is partitioned into an upper sub chamber and a lower main chamber. A thermostat valve is provided between the main chamber and the sub chamber.

  When the temperature of the lubricating oil is below a predetermined value, the thermostat valve is closed. Thereby, only the lubricating oil in the auxiliary chamber circulates in the engine. Thereby, lubricating oil can be warmed at an early stage. Further, when the temperature of the lubricating oil is higher than a predetermined value, the thermostat valve is opened. As a result, the lubricating oil in the main chamber circulates in the engine together with the lubricating oil in the sub chamber. Thereby, the excessive temperature rise of lubricating oil can be suppressed.

Japanese Patent Laid-Open No. 2006-79767

  However, in the structure in which the oil pan is partitioned vertically as described above, the engine becomes large in the vertical direction. Unlike a car, in a saddle-ride type vehicle, the vertical dimension of the engine affects the minimum ground clearance. Therefore, it is not preferable that the engine is enlarged in the vertical direction.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an engine for a saddle-ride type vehicle that can quickly warm the lubricating oil while suppressing an increase in the size of the engine in the vertical direction, and suppresses an excessive increase in the temperature of the lubricating oil. .

  An engine according to one aspect includes a cylinder head, a cylinder, a crankcase, and an oil tank. The cylinder is connected to the cylinder head. The crankcase is connected to the cylinder. The oil tank includes a first oil chamber and a second oil chamber, and is disposed below the crankcase.

  When the temperature of the lubricating oil supplied to the cylinder head is lower than a predetermined temperature, the lubricating oil in the first oil chamber is supplied to the cylinder head. When the temperature of the lubricating oil supplied to the cylinder head is equal to or higher than a predetermined temperature, at least the lubricating oil in the second oil chamber is supplied to the cylinder head.

  The outer surface of the first oil chamber is exposed to the outside of the engine. The outer surface of the second oil chamber is exposed to the outside of the engine. The sum of the surface areas of the inner surface and outer surface of the first oil chamber is smaller than the sum of the surface areas of the inner surface and outer surface of the second oil chamber.

  In the engine according to this aspect, the first oil chamber and the second oil chamber are arranged so that the outer surfaces of the first oil chamber and the second oil chamber are exposed to the outside of the engine. Therefore, it is possible to suppress an increase in the size of the engine in the vertical direction as compared with the case where the first oil chamber and the second oil chamber are arranged one above the other.

  The sum of the surface area of the inner surface of the first oil chamber and the surface area of the outer surface is smaller than the sum of the surface area of the inner surface of the second oil chamber and the surface area of the outer surface. Therefore, when the temperature of the lubricating oil is low, the amount of heat released from the outer surface of the first oil chamber can be kept small by circulating the lubricating oil in the first oil chamber. Thereby, lubricating oil can be warmed at an early stage. Further, when the temperature of the lubricating oil is high, the amount of heat radiation can be increased by circulating the lubricating oil in the second oil chamber. Thereby, the excessive temperature rise of lubricating oil can be suppressed.

  Lubricating oil from the cylinder head may return to the first oil chamber.

  A cam chain chamber may be provided inside the cylinder head, the cylinder, and the crankcase. The first oil chamber may be disposed adjacent to the cam chain chamber. Lubricating oil from the cylinder head may return to the first oil chamber through the cam chain chamber.

  Lubricating oil from the cylinder and / or crankcase may return to the first oil chamber.

  Note that when the lubricating oil returns to the first oil chamber, the lubricating oil may return to the first oil chamber via the second oil chamber. Alternatively, the lubricating oil may return to the first oil chamber without passing through the second oil chamber.

  The engine may further include an oil guide path. The oil guide path may guide lubricating oil from the cylinder and / or crankcase to the first oil chamber.

  The capacity of the first oil chamber may be smaller than the capacity of the second oil chamber.

  The area of the outer surface of the first oil chamber may be smaller than the area of the outer surface of the second oil chamber.

  The area of the inner surface of the first oil chamber may be smaller than the area of the inner surface of the second oil chamber.

  The second oil chamber may include a fin protruding from the inner surface or the outer surface of the second oil chamber.

  The first oil chamber and the second oil chamber may be formed adjacent to each other. The engine may further include a partition wall and a switching valve. The partition wall may be disposed between the first oil chamber and the second oil chamber, and may partition the first oil chamber and the second oil chamber. The switching valve may be provided in the partition wall and communicate or block the first oil chamber and the second oil chamber. When the temperature of the lubricating oil supplied to the cylinder head is lower than a predetermined temperature, the switching valve may shut off the first oil chamber and the second oil chamber. When the temperature of the lubricating oil supplied to the cylinder head is equal to or higher than a predetermined temperature, the switching valve may communicate the first oil chamber and the second oil chamber. A suction port of a supply path for supplying lubricating oil from the oil tank to the cylinder head may be opened in the first oil chamber.

  The switching valve may be a thermostat that closes when the temperature of the lubricating oil is lower than a predetermined temperature and opens when the temperature of the lubricating oil is equal to or higher than the predetermined temperature.

  The engine may further include a cover attached to the crankcase. The partition may be formed integrally with the crankcase or the cover.

  At least a part of the oil tank may be formed integrally with the crankcase.

  The cylinder may be disposed in front of the crankcase. The cylinder head may be disposed in front of the cylinder. The cylinder axis of the cylinder may extend upward and obliquely upward. The first oil chamber may be disposed in front of the second oil chamber.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing the enlargement to the up-down direction of an engine in the engine for saddle-ride type vehicles, while being able to warm lubricating oil at an early stage, it can suppress the excessive temperature rise of lubricating oil. .

It is a mimetic diagram showing composition of an engine concerning an embodiment. It is sectional drawing which shows the structure of a switching valve. It is a schematic diagram which shows arrangement | positioning with the 1st oil chamber and the 2nd oil chamber seen from upper direction. It is a schematic diagram which shows the other example of arrangement | positioning of the 1st oil chamber and the 2nd oil chamber seen from upper direction. It is sectional drawing of the engine which concerns on 1st Example. It is sectional drawing of the engine which concerns on 1st Example. It is sectional drawing of the engine which concerns on 2nd Example. It is sectional drawing of the engine which concerns on 3rd Example. It is sectional drawing of the engine which concerns on 3rd Example. It is sectional drawing of the engine which concerns on 4th Example. It is sectional drawing of the engine which concerns on 4th Example. It is sectional drawing of the engine which concerns on 5th Example. It is a side view showing an example of a saddle riding type vehicle equipped with an engine according to an embodiment. It is a side view which shows the other example of the saddle riding type vehicle by which the engine which concerns on embodiment is mounted. It is a schematic diagram which shows the engine which concerns on a 1st modification. It is a schematic diagram which shows the engine which concerns on a 2nd modification. It is a schematic diagram which shows the engine which concerns on a 3rd modification. It is a schematic diagram which shows the engine which concerns on a 4th modification. It is sectional drawing which shows the switching valve which concerns on a modification.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Drawing 1 is a mimetic diagram showing the composition of engine 1 concerning an embodiment. In the following description, front and rear, left and right, and upper and lower directions mean front and rear, left and right, and upper and lower directions, respectively, when the engine 1 is mounted on a saddle riding type vehicle described later.

  As shown in FIG. 1, the engine 1 has a cylinder head 2, a cylinder 3, a crankcase 4, and an oil tank 5. The cylinder head 2 is disposed in front of the cylinder 3. A cylinder axis Ax1 of the cylinder 3 extends obliquely upward and forward. The cylinder 3 is connected to the cylinder head 2. The cylinder 3 is disposed in front of the crankcase 4. The crankcase 4 is connected to the cylinder 3.

  The oil tank 5 is disposed below the crankcase 4. Lubricating oil is stored in the oil tank 5. The oil tank 5 includes a first oil chamber 5a and a second oil chamber 5b. The outer surface of the first oil chamber 5 a and the outer surface of the second oil chamber 5 b are exposed to the outside of the engine 1. The first oil chamber 5a and the second oil chamber 5b are opened upward.

  The first oil chamber 5a and the second oil chamber 5b are formed adjacent to each other. A partition wall 6 is disposed between the first oil chamber 5 a and the second oil chamber 5 b, and the first oil chamber 5 a and the second oil chamber 5 b are partitioned by the partition wall 6. The partition wall 6 is provided with a communication hole 7. The first oil chamber 5 a and the second oil chamber 5 b communicate with each other through the communication hole 7.

  The engine 1 has a lubricant supply path 8 and can be switched between a first state and a second state. In the first state, the lubricating oil in the first oil chamber 5 a is supplied to the cylinder head 2 via the supply path 8. In the second state, the lubricating oil in the second oil chamber 5 b is supplied to the cylinder head 2 via the supply path 8. The lubricating oil supplied to the cylinder head 2 returns to the first oil chamber 5a via a cam chain chamber, which will be described later, for example. Further, the lubricating oil supplied to the cylinder 3 and the crankcase 4 also returns to the first oil chamber 5a.

  The supply path 8 has a first suction port 11 and a second suction port 12. The first suction port 11 is opened in the first oil chamber 5a. The second suction port 12 opens in the second oil chamber 5b. The engine 1 has an oil pump 13 and a switching valve 14. FIG. 2 is a cross-sectional view showing the structure of the switching valve 14.

  The switching valve 14 is a thermostat that is switched according to the temperature of the lubricating oil supplied to the cylinder head 2, and includes a thermo element 15 and an urging member 16. When the temperature of the lubricating oil supplied to the cylinder head 2 is lower than a predetermined temperature, the thermo element 15 is held at the position shown in FIG. 2 (A) by the urging force of the urging member 16. In this state, the switching valve 14 connects the first suction port 11 and the connection port 17 to the oil pump 13. As a result, the lubricating oil in the first oil chamber 5 a is sucked from the first suction port 11 by the oil pump 13 and supplied to the cylinder head 2 through the supply path 8.

  When the temperature of the lubricating oil is equal to or higher than a predetermined temperature, the thermo element 15 is displaced against the urging force of the urging member 16, and the thermo element 15 moves to the position shown in FIG. In this state, the switching valve 14 connects the second suction port 12 and the connection port 17 to the oil pump 13. As a result, the lubricating oil in the second oil chamber 5 b is sucked from the second suction port 12 by the oil pump 13 and supplied to the cylinder head 2 through the supply path 8.

  FIG. 3 is a schematic diagram showing the arrangement of the first oil chamber 5a and the second oil chamber 5b as viewed from above. As shown in FIG. 3, the first oil chamber 5a and the second oil chamber 5b are arranged in the front-rear direction (hereinafter referred to as “first arrangement example”). The capacity of the first oil chamber 5a is smaller than the capacity of the second oil chamber 5b. The capacity of each oil chamber means the amount of lubricating oil stored in each oil chamber in the engine 1 in the idling state.

  The surface area of the outer surface of the first oil chamber 5a is smaller than the surface area of the outer surface of the second oil chamber 5b. The surface area of the inner surface of the first oil chamber 5a is smaller than the surface area of the inner surface of the second oil chamber 5b. Accordingly, the sum of the surface areas of the inner surface and the outer surface of the first oil chamber 5a is smaller than the sum of the surface areas of the inner surface and the outer surface of the second oil chamber 5b. In addition, the surface area of each oil chamber shall mean the surface area of the range in which lubricating oil is stored in the engine 1 in an idling state.

  In the engine 1 according to the present embodiment, the first oil chamber 5a and the second oil chamber 5b are arranged so that the outer surfaces of the first oil chamber 5a and the second oil chamber 5b are exposed to the outside of the engine 1. Yes. Therefore, compared with the case where the 1st oil chamber 5a and the 2nd oil chamber 5b are piled up and down, the enlargement to the up-down direction of the engine 1 can be suppressed.

  Further, the sum of the surface area of the inner surface and the outer surface of the first oil chamber 5a is smaller than the sum of the surface area of the inner surface and the outer surface of the second oil chamber 5b. Therefore, when the temperature of the lubricating oil supplied to the cylinder head 2 is lower than the predetermined temperature, the amount of heat released from the outer wall surface of the first oil chamber 5a is kept small by circulating the lubricating oil in the first oil chamber 5a. Can do. Thereby, lubricating oil can be warmed at an early stage.

  In particular, when the vehicle is traveling, the discharge amount of the oil pump 13 increases because the engine rotation speed is equal to or higher than the idling rotation speed. For this reason, the amount of lubricating oil in the first oil chamber 5a is further reduced, so that it is difficult to be cooled by the outside air. Thereby, lubricating oil can be warmed at an early stage.

  Further, when the temperature of the lubricating oil is equal to or higher than the predetermined temperature, the heat radiation amount can be increased by circulating the lubricating oil in the second oil chamber 5b. Thereby, the excessive temperature rise of lubricating oil can be suppressed.

  In the above embodiment, the first oil chamber 5a and the second oil chamber 5b are arranged at the front and rear as in the first arrangement example of FIG. However, the arrangement of the first oil chamber 5a and the second oil chamber 5b is not limited to the first arrangement example, and may be changed.

  FIG. 4A shows a second arrangement example. FIG. 4B is a diagram illustrating a third arrangement example. As shown in FIGS. 4A and 4B, the first oil chamber 5a and the second oil chamber 5b may be arranged on the left and right. As shown in FIG. 4A, the first oil chamber 5a may be disposed on the left side and the second oil chamber 5b may be disposed on the right side. Alternatively, as shown in FIG. 4B, the first oil chamber 5a may be disposed on the right side and the second oil chamber 5b may be disposed on the left side.

  FIG. 4C is a diagram showing a fourth arrangement example. FIG. 4D is a diagram illustrating a fifth arrangement example. As shown in FIGS. 4C and 4D, the second oil chamber 5b may be provided across the rear of the first oil chamber 5a and the side of the first oil chamber 5a. As shown in FIG. 4C, the second oil chamber 5b may be provided across the rear of the first oil chamber 5a and the right side of the first oil chamber 5a. Alternatively, as shown in FIG. 4D, the second oil chamber 5b may be provided across the rear of the first oil chamber 5a and the left side of the first oil chamber 5a.

  5 and 6 are cross-sectional views of the engine 1a according to the first embodiment. In the engine 1a according to the first embodiment, the first oil chamber 5a is disposed in front of the second oil chamber 5b as in the first arrangement example described above. The partition wall 6 extends in the left-right direction at the bottom of the crankcase 4 and divides the first oil chamber 5a and the second oil chamber 5b in the front-rear direction. The first oil chamber 5 a and the second oil chamber 5 b are formed integrally with the crankcase 4.

  As shown in FIG. 6, the engine 1a according to the first embodiment has a cam chain chamber 22 in which the cam chain 21 is disposed. The cam chain chamber 22 is provided inside the cylinder head 2, the cylinder 3, and the crankcase 4. The lubricating oil supplied to the cylinder head 2 passes through the cam chain chamber 22 and returns to the first oil chamber 5a.

  As shown in FIG. 5, the engine 1 a according to the first embodiment has an oil guide path 23. The oil guide path 23 guides the lubricating oil from the cylinder 3 and the crankcase 4 to the first oil chamber 5a. The oil guide path 23 is constituted by a part of the partition wall 6. The partition wall 6 divides the first oil chamber 5a and the second oil chamber 5b, and extends to a position between the crankshaft 18 in the crankcase 4 and the second oil chamber 5b. Thereby, the lubricating oil dripped from the crankshaft 18 flows along the partition wall 6 and is guided to the first oil chamber 5a. The partition wall 6 is formed integrally with the crankcase 4. However, the partition wall 6 may be separate from the crankcase 4.

  FIG. 7 is a cross-sectional view of the engine 1b according to the second embodiment. In the engine 1b according to the second embodiment, the first oil chamber 5a and the second oil chamber 5b are arranged on the left and right as in the second arrangement example described above. The partition wall 6 extends in the front-rear direction at the bottom of the crankcase 4 and divides the first oil chamber 5a and the second oil chamber 5b into the left and right.

  The engine 1b according to the second embodiment has a cam chain chamber 22 like the engine 1a according to the first embodiment. The first oil chamber 5 a is disposed adjacent to the cam chain chamber 22, and the lubricating oil supplied to the cylinder head 2 returns to the first oil chamber 5 a through the cam chain chamber 22.

  In the engine 1b according to the second embodiment, the crankcase 4 has a left-right split structure. In that case, it is difficult to integrally form the partition wall 6 with the crankcase 4 by casting. Therefore, the partition wall 6 is preferably formed by a member separate from the crankcase 4 such as a sheet metal. In that case, the partition wall 6 may be fixed to the crankcase 4 by fastening means such as bolts.

  In the engine 1b according to the second embodiment, the first oil chamber 5a and the second oil chamber 5b may be arranged in the above-described fourth arrangement example.

  8 and 9 are cross-sectional views of the engine 1c according to the third embodiment. In the engine 1c according to the third embodiment, the first oil chamber 5a and the second oil chamber 5b are arranged on the left and right as in the third arrangement example described above. In the engine 1 c according to the third embodiment, a cover 24 separate from the crankcase 4 is attached to the crankcase 4. The engine 1 c according to the third embodiment has a generator 25, and the cover 24 covers the generator 25. The first oil chamber 5a is disposed adjacent to a space in which the generator 25 is disposed.

  A part of the first oil chamber 5 a is formed integrally with the cover 24. The first oil chamber 5 a is formed across the crankcase 4 and the cover 24. A part of the second oil chamber 5b may be formed integrally with the cover 24.

  In the engine 1c according to the third embodiment, the first oil chamber 5a and the second oil chamber 5b may be arranged in the fifth arrangement example described above.

  10 and 11 are cross-sectional views of the engine 1d according to the fourth embodiment. In the engine 1d according to the fourth embodiment, the first oil chamber 5a and the second oil chamber 5b are arranged on the left and right as in the third arrangement example described above. The engine 1 d according to the fourth embodiment is a single cylinder engine having a manual transmission 26. As shown in FIG. 10, the manual transmission 26 has a plurality of transmission gears 27 and a clutch 28. The cover 24 covers the clutch 28. In the drawings, only a part of the plurality of transmission gears 27 is denoted by reference numeral 27.

  In the engine 1d according to the fourth embodiment, the first oil chamber 5a is disposed adjacent to a space in which the clutch 28 is disposed. The second oil chamber 5b is disposed adjacent to the space in which the transmission gear 27 is disposed. The first oil chamber 5 a is formed across the cover 24 and the crankcase 4. The second oil chamber 5 b is formed integrally with the crankcase 4.

  An oil guide path 23 is disposed between the space in which the transmission gear 27 is disposed and the second oil chamber 5b. The lubricating oil dropped from the transmission gear 27 flows along the oil guide path 23 and is guided to the first oil chamber 5a.

  In the engine 1d according to the fourth embodiment, the first oil chamber 5a and the second oil chamber 5b may be arranged in the fifth arrangement example described above.

  FIG. 12 is a cross-sectional view of an engine 1e according to the fifth embodiment. In the engine 1e according to the fifth embodiment, the first oil chamber 5a and the second oil chamber 5b are arranged on the left and right as in the third arrangement example described above. The engine 1e according to the fifth embodiment is a multi-cylinder engine having a manual transmission 26.

  In the engine 1e according to the fifth embodiment, an oil pan 29 separate from the crankcase 4 is attached to the crankcase 4. The first oil chamber 5 a and the second oil chamber 5 b are formed integrally with the oil pan 29. The partition wall 6 is formed integrally with the oil pan 29. Alternatively, the partition wall 6 may be separate from the oil pan 29.

  Similar to the engine 1d according to the fourth embodiment, in the engine 1e according to the fifth embodiment, the first oil chamber 5a is disposed adjacent to the space in which the clutch 28 is disposed. The second oil chamber 5b is disposed adjacent to a space in which the plurality of transmission gears 27 of the manual transmission 26 are disposed. An oil guide path 23 is arranged between the space in which the plurality of transmission gears 27 are arranged and the second oil chamber 5b, and the lubricating oil dropped from the plurality of transmission gears 27 is supplied to the first oil chamber. Guide to 5a.

  In the engine 1e according to the fifth embodiment, the first oil chamber 5a and the second oil chamber 5b may be arranged in the fifth arrangement example described above. Alternatively, in the engine 1e according to the fifth embodiment, the first oil chamber 5a and the second oil chamber 5b may be arranged in the first arrangement example described above.

  Next, a straddle-type vehicle on which the engine 1 according to the above embodiment is mounted will be described. FIG. 13 is a side view showing an example of a saddle riding type vehicle 100 on which the engine 1 is mounted. The saddle riding type vehicle 100 is a scooter type motorcycle. The saddle riding type vehicle 100 includes a steering device 101, a vehicle main body 102, a power unit 103, a front wheel 104, a rear wheel 105, and a seat 106.

  The steering device 101 includes a front fork 107. The front fork 107 supports the front wheel 104 in a rotatable manner. A handle 108 is provided on the upper portion of the steering device 101.

  The vehicle main body 102 includes a front cover 131, a rear cover 133, and a lower cover 134. The front cover 131 covers the steering device 101 from the front and rear. The rear cover 133 is disposed below the seat 106. The lower cover 134 is disposed between the front cover 131 and the rear cover 133. The upper surface of the lower cover 134 includes a foot board 135. The footboard 135 is arranged so that the rider's legs are placed thereon. The foot board 135 has a flat shape. The foot board 135 may have a flat shape in the vehicle width direction. Or the center part in the vehicle width direction of the foot board 135 may be a convex shape upward.

  The power unit 103 is disposed below the seat 106. The power unit 103 is swingably supported by the vehicle main body 102. The power unit 103 supports the rear wheel 105 in a rotatable manner. The power unit 103 includes the engine 1. The engine 1 is disposed below the seat 106. The cylinder axis Ax1 of the engine 1 is inclined forward and upward.

  FIG. 14 is a side view showing a saddle-ride type vehicle 200 according to another example in which the engine 1 according to the above embodiment is mounted. The saddle riding type vehicle 200 is a so-called sports type motorcycle. The saddle riding type vehicle 200 includes a fuel tank 201, a seat 202, and a vehicle body frame 203.

  The fuel tank 201, the seat 202, and the engine 1 are supported by the vehicle body frame 203. The fuel tank 201 is disposed in front of the seat 202. The engine 1 is disposed below the fuel tank 2.

  The saddle riding type vehicle 200 includes a steering device 204, a front wheel 205, a handle 206, and a headlight unit 207. The steering device 204 includes a front fork 209. The front fork 209 supports the front wheel 205 in a rotatable manner. The handle 206 is provided on the steering device 204. The headlight unit 207 is disposed in front of the fuel tank 201.

  The saddle riding type vehicle 200 includes a swing arm 211 and a rear wheel 212. The swing arm 211 extends rearward from the vehicle body frame 203. The swing arm 211 is connected to the vehicle body frame 203 so as to be swingable up and down. The rear wheel 212 is rotatably supported at the rear part of the swing arm 211.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of invention.

  The switching valve 14 is not limited to a thermostat, and may be an electric motor movable valve or a hydraulic movable valve. The oil guide path 23 may guide only the lubricating oil from the cylinder 3 to the first oil chamber 5a. Alternatively, the oil guide path 23 may guide only the lubricating oil from the crankcase 4 to the first oil chamber 5a.

  In the above embodiment, when the lubricating oil supplied to the cylinder head 2 is at a predetermined temperature or higher, the lubricating oil is supplied from the second oil chamber 5b. However, when the lubricating oil supplied to the cylinder head 2 is equal to or higher than a predetermined temperature, the lubricating oil may be supplied from both the first oil chamber 5a and the second oil chamber 5b. FIG. 15 is a schematic diagram showing the engine 1 according to the first modification.

  As shown in FIG. 15, the engine 1 according to the first modification has a switching valve 14 provided in the partition wall 6. The switching valve 14 communicates or blocks the first oil chamber 5a and the second oil chamber 5b. The switching valve 14 is a thermostat that is closed when the temperature of the lubricating oil is lower than a predetermined temperature and is opened when the temperature of the lubricating oil is equal to or higher than the predetermined temperature.

  A suction port 31 of a supply path 8 for supplying lubricating oil from the oil tank 5 to the cylinder head 2 opens into the first oil chamber 5a. When the lubricating oil supplied to the cylinder head 2 is lower than a predetermined temperature, the switching valve 14 shuts off the first oil chamber 5a and the second oil chamber 5b. As a result, the oil pump 13 supplies the lubricating oil in the first oil chamber 5 a to the cylinder head 2. Therefore, the lubricating oil in the first oil chamber 5a circulates, so that the lubricating oil can be warmed up early.

  When the lubricating oil supplied to the cylinder head 2 is above a predetermined temperature, the switching valve 14 communicates the first oil chamber 5a and the second oil chamber 5b. Thereby, the oil pump 13 supplies the lubricating oil in the first oil chamber 5a and the lubricating oil in the second oil chamber 5b to the cylinder head 2. Therefore, the lubricating oil in the first oil chamber 5a and the lubricating oil in the second oil chamber 5b circulate, so that an excessive temperature rise of the lubricating oil can be suppressed.

  In the above embodiment, the supply of the lubricating oil in the engine 1 is switched by the switching valve 14, but may be switched by means other than the switching valve 14. For example, FIG. 16 is a schematic diagram showing an engine 1 according to a second modification.

  In the engine 1 according to the second modification, independent oil pumps 13a and 13b are provided in the first oil chamber 5a and the second oil chamber 5b, respectively. That is, the engine 1 according to the second modification has a first oil pump 13a and a second oil pump 13b. The first oil pump 13a sucks the lubricating oil in the first oil chamber 5a from the first suction port 11. The second oil pump 13b sucks the lubricating oil in the second oil chamber 5b from the second suction port 12.

  When the temperature of the lubricating oil supplied to the cylinder head 2 is lower than a predetermined temperature, the first oil pump 13a is driven. As a result, the lubricating oil in the first oil chamber 5 a is supplied to the cylinder head 2. When the temperature of the lubricating oil supplied to the cylinder head 2 is equal to or higher than a predetermined temperature, the first oil pump 13a and the second oil pump 13b are driven. As a result, the lubricating oil in the first oil chamber 5 a and the lubricating oil in the second oil chamber 5 b are supplied to the cylinder head 2.

  Note that when the temperature of the lubricating oil supplied to the cylinder head 2 is equal to or higher than a predetermined temperature, the first oil pump 13a may not be driven and only the second oil pump 13b may be driven.

  In the above embodiment, the first oil chamber 5a is disposed in front of the second oil chamber 5b. However, the first oil chamber 5a may be disposed behind the second oil chamber 5b. For example, FIG. 17 is a schematic diagram showing an engine 1 according to a third modification.

  As shown in FIG. 17, in the engine 1 according to the third modification, the first oil chamber 5a is disposed behind the second oil chamber 5b. An oil guide path 32 is disposed above the second oil chamber 5b. The oil guide path 32 guides the lubricating oil from the cylinder head 2, the cylinder 3, or the crankcase 4 to the first oil chamber 5a.

  The surface area of the second oil chamber 5b may be increased by providing fins in the second oil chamber 5b. For example, FIG. 18 is a schematic diagram showing an engine 1 according to a fourth modification. As shown in FIG. 18, the second oil chamber 5b is provided with a plurality of fins 33 protruding from the inner surface of the second oil chamber 5b. By providing the fins 33 in the second oil chamber 5b, the surface area of the inner surface of the second oil chamber 5b is enlarged. Thereby, the heat radiation amount in the second oil chamber 5b can be increased.

  The fins 33 may protrude from the outer surface of the second oil chamber 5b. Thereby, the surface area of the outer surface of the second oil chamber 5b can be increased. Alternatively, both the fin 33 protruding from the outer surface of the second oil chamber 5b and the fin 33 protruding from the inner surface of the second oil chamber 5b may be provided.

  The structure of the switching valve 14 may be changed. For example, the thermo element 15 of the switching valve 14 may be switchable to an intermediate position for sucking the lubricating oil in both the first oil chamber 5a and the second oil chamber 5b. Specifically, when the thermo element 15 is in the intermediate position shown in FIG. 19, the switching valve 14 connects the first suction port 11 and the connection port 17, and connects the second suction port 12 and the connection port 17. . As a result, the lubricating oil in the first oil chamber 5 a and the lubricating oil in the second oil chamber 5 b are sucked by the oil pump 13 and supplied to the cylinder head 2 via the supply path 8.

  ADVANTAGE OF THE INVENTION According to this invention, while suppressing the enlargement to the up-down direction of an engine in the engine for saddle-ride type vehicles, while being able to warm lubricating oil at an early stage, it can suppress the excessive temperature rise of lubricating oil. .

2 Cylinder head 3 Cylinder 4 Crankcase 5a First oil chamber 5b Second oil chamber 5 Oil tank 22 Cam chain chamber 23, 32 Oil guide path 33 Fin 6 Bulkhead 14 Switching valve

Claims (14)

A cylinder head;
A cylinder connected to the cylinder head;
A crankcase connected to the cylinder;
An oil tank including a first oil chamber and a second oil chamber and disposed below the crankcase;
With
When the temperature of the lubricating oil supplied to the cylinder head is lower than a predetermined temperature, the lubricating oil in the first oil chamber is supplied to the cylinder head,
When the temperature of the lubricating oil supplied to the cylinder head is equal to or higher than the predetermined temperature, at least the lubricating oil in the second oil chamber is supplied to the cylinder head,
The outer surface of the first oil chamber is exposed to the outside of the engine,
The outer surface of the second oil chamber is exposed to the outside of the engine,
The sum of the surface areas of the inner surface and the outer surface of the first oil chamber is smaller than the sum of the surface areas of the inner surface and the outer surface of the second oil chamber,
engine. The lubricating oil from the cylinder head returns to the first oil chamber;
The engine according to claim 1. A cam chain chamber is provided inside the cylinder head, the cylinder, and the crankcase,
The first oil chamber is disposed adjacent to the cam chain chamber;
The lubricating oil from the cylinder head passes through the cam chain chamber and returns to the first oil chamber.
The engine according to claim 1 or 2. Lubricating oil from the cylinder and / or the crankcase returns to the first oil chamber,
The engine according to any one of claims 1 to 3. An oil guide path for guiding lubricating oil from the cylinder and / or the crankcase to the first oil chamber;
The engine according to any one of claims 1 to 4. The capacity of the first oil chamber is smaller than the capacity of the second oil chamber,
The engine according to any one of claims 1 to 5. The area of the outer surface of the first oil chamber is smaller than the area of the outer surface of the second oil chamber,
The engine according to any one of claims 1 to 6. The area of the inner surface of the first oil chamber is smaller than the area of the inner surface of the second oil chamber,
The engine according to any one of claims 1 to 7. The second oil chamber includes a fin protruding from the inner surface or the outer surface of the second oil chamber.
The engine according to any one of claims 1 to 8. The first oil chamber and the second oil chamber are formed adjacent to each other,
A partition wall disposed between the first oil chamber and the second oil chamber, and partitioning the first oil chamber and the second oil chamber;
A switching valve that is provided in the partition wall and communicates or blocks the first oil chamber and the second oil chamber;
Further comprising
When the temperature of the lubricating oil supplied to the cylinder head is lower than the predetermined temperature, the switching valve shuts off the first oil chamber and the second oil chamber,
When the temperature of the lubricating oil supplied to the cylinder head is equal to or higher than the predetermined temperature, the switching valve communicates the first oil chamber and the second oil chamber,
A suction port of a supply path for supplying lubricating oil from the oil tank to the cylinder head opens into the first oil chamber;
The engine according to any one of claims 1 to 9. The switching valve is a thermostat that is closed when the temperature of the lubricating oil is lower than the predetermined temperature, and is opened when the temperature of the lubricating oil is equal to or higher than the predetermined temperature.
The engine according to claim 10. Further comprising a cover attached to the crankcase,
The partition is formed integrally with the crankcase or the cover.
The engine according to claim 10 or 11. At least a part of the oil tank is formed integrally with the crankcase,
The engine according to any one of claims 1 to 11. The cylinder is disposed in front of the crankcase;
The cylinder head is disposed in front of the cylinder;
The cylinder axis of the cylinder extends obliquely upward and forward,
The first oil chamber is disposed in front of the second oil chamber;
The engine according to any one of claims 1 to 13.